Field of the Invention
This invention relates, in general, to vehicle anti-theft devices.
Vehicle security apparatus are commonly employed to indicate the unauthorized access to and/or prevent the operation of vehicles when unauthorized access to a vehicle housing a vehicle security apparatus is attempted. Such apparatus employ sensors which are mounted on the vehicle to detect access to the vehicle, such as the opening of a door, trunk, hood, window, or movement of the vehicle caused by jacking the vehicle, breaking a window, etc. Such security apparatus activate an alarm when such an intrusion is attempted, such as by beeping the vehicle's horn, energizing a siren mounted on the vehicle and/or flashing the vehicles lights.
The known vehicle security apparatus are activated or armed by a variety of means. External key locks may be employed to energize the security apparatus after the operator has left the vehicle. Such apparatus have also been activated by the closing and locking of a vehicle's doors or via a remote, hand-held transmitter carried by the vehicle operator which is activated externally from the vehicle to arm and disarm the security system.
In the latter type of vehicle security apparatus, the hand-held transmitter emits a coded signal which is detected by a receiver mounted within the vehicle. The receiver recognizes the coded signal and compares it to a stored code to recognize a specific transmitter and, thereupon, to arm or activate the security apparatus upon receipt of the specific coded signal. A second signal from the transmitter is employed to disarm or deactivate the security apparatus.
When the system is armed, any attempt to gain access to the vehicle and/or to move or operate the vehicle causes the receiver to activate an alarm and/or disconnect the starter system to prevent operation of the vehicle. It is also known to employ various additional features in such security apparatus which automatically lock and unlock the vehicles doors coincident with arming and disarming of the security apparatus, latch and unlatch the vehicle's trunk and/or hood latches and/or operate various electrical elements, such as the interior lights of the vehicle.
The known vehicle security apparatus utilize a limited number of discrete codes which are matched between a specific transmitter and a specific receiver. These codes are selected and installed by the manufacturer of the vehicle security apparatus and are not easily altered. Thus, the loss of a transmitter requires that a new transmitter be coded with the predetermined code of a specific receiver mounted in a vehicle. Due to the large number of binary bits required to provide the necessary thousands or millions of discrete codes, the task of programming a transmitter code to match a specific receiver becomes a time consuming and tedious task.
Furthermore, in two car families, separate transmitters are required for each vehicle having a security apparatus mounted therein. This proves cumbersome as a single operator may desire from time to time to arm or disarm the security apparatus of either vehicle.
Thus, it would be desirable to provide a vehicle security apparatus which utilizes one of a large number of discrete codes. It would also be desirable to provide a vehicle security apparatus in which the codes are easily programmed in the transmitter and receiver sections of the vehicle security apparatus. It would also be desirable to provide a vehicle security apparatus in which the receiver can learn or be programmed at any time with the code of a specific transmitter. It would also be desirable to provide a vehicle security apparatus which effectively prevents the operation of the vehicle and/or activates an alarm when the security apparatus is armed and access to the vehicle is attempted. Finally, it would be desirable to provide a vehicle security apparatus in which various electrical components of the vehicle are automatically controlled coincident with the arming and disarming of the security apparatus.